a worst-case (low harvesting density of 0.6 g/l per 6 d, an average of the lowest
values found in the literature), a moderate case (3.0 g/l per 6 d, (literature and
project result average) and an optimal case (5.0 g/l per 6 d, an average of the
maximum values found in the literature). The scenarios modelled the biomass
productivity and determined the area and water requirements in the three situations.
This gave a range and understanding of the minimum and maximum capacity of
the cultivation facility area.
The results showed that with the algal production rates presented, the reserved
area in Kujala (2.2 ha) was far too small for the targeted biomass production
60 000 t/a, (Kujalan Komposti Oy 2011). In addition the corresponding water consumption
would be 14 700–44 100 m3 per year of raw waste water, meaning significant
pumping and treatment costs (Järvelin 2011).
Key findings: